Mapping Wetland Loss in the Niger Delta Using Multi-Temporal Satellite Imagery

The Niger Delta region of South South Nigeria contains some of Africa's most ecologically significant wetlands, yet decades of oil exploration and agricultural conversion have caused substantial wetland loss. This study maps wetland extent and tracks spatial changes across selected areas in Delta and Bayelsa states using Landsat imagery from 2010, 2016, and 2022. The Normalised Difference Water Index and the Modified Normalised Difference Water Index are used to delineate open water and vegetated wetlands. Supervised classification using Support Vector Machine produces land cover maps validated against field data and aerial photograph interpretation. Results indicate a net loss of approximately 18 percent of wetland cover over the 12-year period, driven primarily by hydrocarbon infrastructure expansion and artisanal refining activities. The spatial pattern of loss is concentrated near major oil field clusters in Warri South-West and Sagbama LGAs. The study recommends integrating satellite-based wetland monitoring into the National Oil Spill Detection and Response Agency's operational framework. Findings provide baseline data for wetland conservation planning and environmental impact assessment in the Niger Delta. Keywords: wetland mapping, Niger Delta, land cover change, remote sensing, environmental monitoring